Back to the 21st century, I have toured many thousands of miles on platforms. I like to minimise the number of pairs of shoes I take, I like having footwear I can go hiking in, I like being able to just get off the bike and walk round some town or village or investigate some mediaeval castle or cathedral in comfort (and quietly - they often have marble floors) without swapping out shoes. My current setup is a pair of Merrill walking shoes - light but pretty rigid "vibram" soles - and Shimano Saint MTB/BMX pedals. The latter are excellent. Big platform, fractionally concave, with foot retention ranging from good to extremely good depending on how high you set the screw-in spikes. There is no loss of pedalling efficiency and to suggest they are somehow "borderline unsafe" is absurd. It's a tour. I'm not going to be bumping up against other riders like in a crit, nor am I going to be doing any Cavendish-esque finishing sprints.
I save the clipless pedals for the road bikes. Others clearly have different approaches, but it works for me.